BOB: Business Objects Board
Not endorsed by or affiliated with SAP

Register | Login 

Want to sponsor BOB? 
Want to sponsor BOB? (Opens a new window)  

General Notice: BOB is going to retire...please see details here.
General Notice: No events within the next 45 days.

SAP HANA - does data storage block size impact IO so much?


 
Search this topic... | Search Other Products... | Search Box
Register or Login to Post    Forum Index -> Other Products  Previous TopicPrint TopicNext Topic
Author Message
jameszhjw
Forum Member
Forum Member



Joined: 25 Jul 2013

Posts: 1



PostPosted: Thu Jul 25, 2013 2:20 pm 
Post subject: SAP HANA - does data storage block size impact IO so much?

I am doing SAP HANA performance testing.

I used the testing file size as 1GB, 5GB, 10GB and etc.
In each file size, I tested different block sizes for Log and Data - I tried 4k, 16k, 64k, 1MB, 16MB and 64MB block size.


The result is:
1. the file size (1GB, 5GB or 10GB) doesn't bring much difference.
2. The block size shows very different results: when the block size is less than 1MB, the IO performances are very poor - the Write IO is even poorer than Read IO; when the block size is more than 1MB, the IO performance improves signicifantly.

I was wondering why the block size may impact the IO so much?
And, if using block size less than 1MB, what factors can I change to improve the IO performance so that it's comparable with that of block sizes more than 1MB?

Thanks!
Back to top
Marek Chladny
Forum Advocate
Forum Advocate



Joined: 27 Nov 2003

Posts: 19319
Location: Bratislava


flag
PostPosted: Thu Jul 25, 2013 2:24 pm 
Post subject: Re: SAP HANA - does data storage block size impact IO so muc

[Moderator Note: Moved from General Discussion to Other Products]

And welcome to Bicon_mrgreen.gifB!
Back to top
richardcottave
Principal Member
Principal Member



Joined: 30 Mar 2006

Posts: 305



PostPosted: Thu Jul 25, 2013 2:40 pm 
Post subject: Re: SAP HANA - does data storage block size impact IO so muc

I don't know about HANA but if it is analogous to a disk drive the block size has an impact on performance. A smaller block size requires more blocks to store a file. This in turn requires more reads and writes to the file allocation table so performance is degraded. With a disk drive you can optimize block size by calculating the average file size then make your block size as close to the average file size as possible. I have no clue if HANA works the same way though.
Back to top
Display posts from previous:   
Register or Login to Post    Forum Index -> Other Products  Previous TopicPrint TopicNext Topic
Page 1 of 1 All times are GMT - 5 Hours
 
Jump to:  

Index | About | FAQ | RAG | Privacy | Search |  Register |  Login 

Get community updates via Twitter:

Not endorsed by or affiliated with SAP
Powered by phpBB © phpBB Group
Generated in 0.0529 seconds using 18 queries. (SQL 0.0285 Parse 0.0008 Other 0.0235)
CCBot/2.0 (https://commoncrawl.org/faq/)
Hosted by ForumTopics.com | Terms of Service
phpBB Customizations by the phpBBDoctor.com
Shameless plug for MomentsOfLight.com Moments of Light Logo